|Publication number||US4384318 A|
|Application number||US 06/219,789|
|Publication date||May 17, 1983|
|Filing date||Dec 24, 1980|
|Priority date||Dec 24, 1980|
|Publication number||06219789, 219789, US 4384318 A, US 4384318A, US-A-4384318, US4384318 A, US4384318A|
|Inventors||Robert L. Reibling|
|Original Assignee||Kidde Consumer Durables Corp.|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (9), Referenced by (24), Classifications (25), Legal Events (5)|
|External Links: USPTO, USPTO Assignment, Espacenet|
Task lighting is lighting supplementary to general ambient lighting to provide additional illumination of a work surface, such as, for example, a work bench or a counter top. Work surfaces located under cabinets or shelves will have much of the ambient lighting blocked out. Therefore, a task light is necessary to adequately illuminate those surfaces. Also, many times the ambient lighting is insufficient to provide adequate illumination of a work surface, and, therefore, a task light is necessary to supplement the ambient lighting.
Ideally, a task light must perform two major functions: (1) it must increase the overall illumination level on the work surface, and (2) it must produce a glare-free visual environment. In addition, the ideal task light must have other attributes, such as a low profile, high light output and efficient optical system.
Prior task light designs incorporate one or two fluorescent lamp tubes in lengths ranging from 9 inches to 48 inches. The lamp was either exposed or was mounted in an enclosure having a clear lens, a prismed lens or an "egg-crate" baffle. Such task light fixtures are typically mounted under cabinets or shelves or are suspended above the work surface, and extend laterally along most of the length of the work surface. Such fixtures usually provide adequate illumination, but do not address the problem of glare control. When such fixtures are located directly in an angular line with the eye, objectionable reflective glare will be experienced. This is annoying and tiring to the viewer.
Although reflectors and louvers have long been used in lighting fixtures, prior designs have never been able to achieve both major functions of a task light. For example, U.S. Pat. No. 2,591,251 teaches the use of vertical baffles arranged in a typical "egg-crate" configuration. U.S. Pat. No. 2,683,799 teaches the use of both angled reflectors and vertical louvers with prismatic surfaces which gradually taper down along the length of the louver. U.S. Pat. No. 2,745,001 also teaches the use of vertical louvers to difuse the light. The configuration disclosed in a latice configuration at specific dimensions. U.S. Pat. No. 3,169,710 is very similar to U.S. Pat. No. 2,745,001 but is not as specific in describing the latice configuration. U.S. Pat. No. 3,187,660 also teaches the use of an angled reflector. British Pat. No. 944,201 teaches the use of angled louvers of prismatic form arranged vertically, similar to U.S. Pat. No. 2,683,799. None of the prior art devices achieve a controlled, glare-free illumination pattern.
The task light fixture of the present invention consists of three major components: a housing, a chassis and a louver assembly. The housing has an open bottom. The chassis is supported in the housing and includes an open bottom reflector. The reflector is arranged and shaped to direct lumen output of a light source in zonal segments for vertical and lateral distribution. A light source is supported in the housing beneath the reflector. A louver assembly is supported adjacent the open bottom of the housing. The louver assembly is arranged so that it can direct portions of the lumen output from the light source in a plurality of inclined planes.
An object of the present invention is to provide increased illumination of a work surface without also producing objectionable glare.
Another object of the present invention is to provide increased, glare-free illumination in a fixture having a low profile, high light output and an efficient optical system. A further object of the present invention is to provide a task light fixture having mechanical flexibility to adapt to various methods of mounting, for example, under shelves, on walls, free standing, clamp-on and pendent mounting.
For the purpose of illustrating the invention, there is shown in the drawing a form which is presently preferred; it being understood, however, that this invention is not limited to the precise arrangements and instrumentalities shown.
FIG. 1 is a perspective view of the present invention.
FIG. 2 is an exploded view of the light fixture.
FIG. 3 is a longitudinal sectional view taken along the line 3--3 in FIG. 1.
FIG. 4 is a sectional view taken along the line 4--4 in FIG. 3.
Referring to the drawings, wherein like numerals indicate like elements, there is shown in FIG. 1 a task light fixture 10 in accordance with the present invention and mounted on the bottom surface of a support 12. The support 12 may be a shelf, the bottom of a cabinet mounted on a wall, or the like. Fixture 10 has a low profile whereby its height in elevation is approximately 2 to 21/2 inches. As shown more clearly in FIG. 2, task light fixture 10 consists of three major components, namely a housing 14, a chasis 16, and a louver assembly 20.
Housing 14 is made in one piece of sheet metal or plastic and has a top wall 22 connected to end walls 24 and 26 and side walls 28 and 30. End wall 24 has a hole 32 for accommodating electrical wiring as will be made clear hereinafter. At least one and preferably two spacers or brackets 36 are riveted or otherwise secured at their middle zone to top wall 22 within housing 14. Each spacer or bracket 36 has downwardly angled end portions 76 and extends transversely of the housing 14 as shown in FIGS. 2 and 4.
Chassis 16 is preassembled as a unit and includes end walls 40 and 42 interconnected by a reflector 44. End wall 40 has beveled corners 70 which cooperate with the inner surface of housing 14 to define wireways 68. The upper corners 72 of end wall 42 are similarly beveled. End wall 40 has a hole 34 for accommodating an electrical switch as will be made clear hereinafter. A spring clip 46 is mounted in the center portion of end wall 40. As shown most clearly in FIG. 3, an electrical ballast 64 for the light source 18 is secured to end wall 40.
As shown in FIGS. 2 and 3, an electrical socket 50 is mounted in the center of end wall 42. A starter 52 for light source 18 is removably mounted in socket 50. Two electrical sockets 48 for light source 18 are mounted on end wall 42 on either side of socket 50. Two spring clips 46 are secured to end wall 42 and are located approximately below sockets 48.
End wall 40 and end wall 42 are interconnected by reflector 44. As shown most clearly in FIG. 4, reflector 44 has a cross-section which is a symmetrical stepped angular shape to redirect the light output of light source 18 in zonal segments. Reflector 44 is provided with mounting holes 74 which cooperate with holes 38 in spacers 36 to enable chassis 16 to be mounted within housing 14.
Light source 18 is a conventional fluorescent tube in the shape of a U. The U-shape configuration permits maximum light output in a minimum amount of space. By way of example, the light source 18 would typically have a wattage rating of 15 W or 25 W and a preferred length of 9 to 10 inches. Light source 18 is mounted in sockets 48, which are mounted on end wall 42 of chassis 16.
Louver assembly 20 is an integral one-piece structure of sheet metal or plastic. Louver assembly 20 consists of a frame 56 which supports a plurality of louvers 58. The louvers 58 are attached to frame 56 so that the angle θ between the plane of the louvers 58 and the longitudinal axis of the task light 10 is about 30°. Louver assembly 20 is provided with three suitable openings 54 to engage the spring clips 46 in chassis 16 for removably securing louver assembly 20 to chassis 16. It is preferred that the louver assembly 20 have a chromed surface finish which is highly specular in appearance, or have reflectivity equal to a specular alzak finish on aluminum.
As shown in FIG. 3, an electrical switch 62 is mounted to end wall 40 of chassis 16. Switch 62 is a typical on/off switch for light source 18. Electrical power is provided to the task light 10 by means of electrical conductor 66, which is connected to ballast 64 in the conventional manner. A clip 60 is mounted to reflector 44 in the center portion of the end of reflector 44 adjacent end wall 40. Clip 60 removably secures light source 18 to chassis 16.
In use, the angular stepped shaped of reflector 44 directs the light output of light source 18 in zonal segments for vertical and lateral distribution. The louver assembly 20 redirects portions of the light generated by light source 18 in a plurality of inclined planes, so that the vertical beam component (0° axis) of the light has maximum candle power at 40° and the lateral beam component (90° axis) has maximum candle power at 30°. The combination of light source 18, reflector 44 and louver assembly 20 produces a controlled light pattern shape of high efficiency and illumination levels, while also providing beam direction and cut off to eliminate glare.
It will be appreciated that the present invention performs the two major task lighting functions, increased illumination and elimination of glare.
The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification, as indicating the scope of the invention.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US2591251 *||Dec 23, 1949||Apr 1, 1952||Louis Gilman||Fluorescent lighting fixture with light baffles|
|US2683799 *||May 10, 1951||Jul 13, 1954||Day Brite Lighting Inc||Electric lighting fixture with louver members|
|US2745001 *||Dec 15, 1951||May 8, 1956||Edwin F Guth||Light diffusors for illuminating devices|
|US3094287 *||Dec 18, 1959||Jun 18, 1963||Transolite Corp||Fluorescent tube fixture and hardware|
|US3169710 *||Mar 16, 1962||Feb 16, 1965||Willis L Lipscomb||Lighting fixture|
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|US4254449 *||Oct 10, 1978||Mar 3, 1981||Conwed Corporation||Task lighting system|
|Citing Patent||Filing date||Publication date||Applicant||Title|
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|US5008791 *||Jul 19, 1990||Apr 16, 1991||Caferro Ronald N||Low direct glare and wall wash parabolic lighting grid|
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|US7568818 *||Apr 17, 2006||Aug 4, 2009||Sylvan R. Shemitz Designs, Inc.||Lamp distribution modifier and luminaire having the same|
|US8201956||Apr 29, 2010||Jun 19, 2012||3M Innovative Properties Company||Task light|
|US20030063467 *||Sep 17, 2002||Apr 3, 2003||Zumtobel Staff Gmbh & Co. Kg||Recessed luminaire having a dome-shaped reflector|
|US20030218875 *||May 21, 2002||Nov 27, 2003||Mofid Bissada||Lighting system and lamp with optimal position placement for television, news and motion picture studio|
|US20060232960 *||Apr 17, 2006||Oct 19, 2006||David Pfund||Lamp distribution modifier and luminaire having the same|
|US20070223229 *||May 3, 2005||Sep 27, 2007||Koninklijke Philips Electronics, N.V.||Luminaire and Lamellae Louver Therefor|
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|US20100277888 *||Apr 29, 2010||Nov 4, 2010||3M Innovative Properties Company||Task light|
|US20130182406 *||Jan 14, 2013||Jul 18, 2013||Wintek Corporation||Polarized light source module|
|EP0179453A1 *||Oct 23, 1985||Apr 30, 1986||ITT Reiss International GmbH||Lighting fixture for humid environments|
|WO2001069128A1 *||Mar 1, 2001||Sep 20, 2001||Zumtobel Staff Gmbh & Co. Kg||Built-in lamp with a dome-shaped reflector|
|WO2006113691A2 *||Apr 17, 2006||Oct 26, 2006||Sylvan R. Shemitz Designs, Inc.||Lamp distribution modifier and luminaire having the same|
|WO2006113691A3 *||Apr 17, 2006||Nov 22, 2007||Sylvan R Shemitz Designs Inc||Lamp distribution modifier and luminaire having the same|
|WO2007118140A2 *||Apr 5, 2007||Oct 18, 2007||True Manufacturing Co., Inc.||Refrigerator with cladding and visual effects|
|WO2007118140A3 *||Apr 5, 2007||Dec 18, 2008||True Mfg Co Inc||Refrigerator with cladding and visual effects|
|U.S. Classification||362/216, 362/362, 362/346, 362/354, 362/342, 362/290|
|International Classification||F21V19/00, F21V23/02, F21V23/04, F21V17/16, F21V11/02|
|Cooperative Classification||F21V23/04, F21Y2103/37, F21W2131/402, F21V19/0095, F21V11/02, F21S6/003, F21V17/164, F21V23/02|
|European Classification||F21S6/00D2, F21V23/02, F21V23/04, F21V17/16B, F21V11/02, F21V19/00F2|
|Oct 10, 1986||FPAY||Fee payment|
Year of fee payment: 4
|Oct 5, 1987||AS||Assignment|
Owner name: SPAULDING LIGHTING, INC.,
Free format text: CHANGE OF NAME;ASSIGNOR:WHITEWAY MANUFACTURING CO.;REEL/FRAME:004772/0174
Effective date: 19850525
Owner name: SPAULDING LIGHTING, INC.
Free format text: CHANGE OF NAME;ASSIGNOR:WHITEWAY MANUFACTURING CO.;REEL/FRAME:004772/0174
Effective date: 19850525
|Dec 18, 1990||REMI||Maintenance fee reminder mailed|
|May 19, 1991||LAPS||Lapse for failure to pay maintenance fees|
|Jul 30, 1991||FP||Expired due to failure to pay maintenance fee|
Effective date: 19910519